The present invention relates generally to magnetic clip devices and more particularly to a magnetic clip assembly for use in the manufacture of a dynamoelectric machine such as an electric generator.
A typical electric generator includes a rotor mounted within a stator. The rotor is an electromagnet that includes a multiple of field coils having a plurality of turns (windings or layers) typically made of copper or aluminum. A body of the rotor, typically made of steel, includes a multiple of axial slots disposed therein. The plurality of turns of field coils are arranged within each of these axial slots. Each of the field coils is electrically and mechanically isolated from the axial slots by slot insulation known as slot armor. The slot insulation serves to position and protect the field coils from electrical contact with the rotor body. Specifically, the slot insulation isolates the sides of the field coils. The field coils produce a magnetic flux pattern when supplied with electrical current. A turbine (e.g., a gas or steam turbine) rotates the rotor including the field coils such that the magnetic flux pattern interacts with windings of the stator to generate electric power.
During the manufacturing of an electric generator, a problem can arise during the winding (assembly process) of the field coils (i.e., placement of the coil windings in the axial slots against the side surfaces of the slot insulation). In particular, the slot insulation tends to become damaged (i.e., broken or frayed) as the turns of field coils are installed in the axial slots. That is, the turns of field coils contact edges of the slot insulation during installation and sometimes break or fray the slot insulation, necessitating replacement of the insulation. Because the ends of each installed field coil have to be brazed, the labor costs in unbrazing and removing the coils in order to replace damaged slot insulation can be, excessive especially if multiple turns of a coil have already been installed in the axial slots. In addition to excessive labor costs, there are delays in manufacturing the electric generators when it becomes necessary to replace slot insulation.